In factory automation, production facilities placed in a factory are controlled by a field network over which various types of slave devices which collect and control data of the production facilities and a master device which conducts central control on these slave devices are connected to each other via a communication bus. FIG. 13 is a diagram showing an example of configuration of the field network. In FIG. 13, a field network 100 is built if a master device 200 (programmable logic controller: PLC) and a plurality of slave devices 300 are connected to each other directly or indirectly via a cable 400 or an I/O unit 500 that is included in each of the devices 300. The slave devices 300 may each include a power supply unit, a motor unit, a counter unit, an image unit, a communication unit, an I/O unit, etc. The communication bus may take on various topologies such as a line, a daisy chain, a tree, and a start, depending on the standard of the field network. To the master device 200, a management device 600 may be connected which is used by a user to set operations of the master device 200, display operation states of the field network 100, and design a network system. The management device 600 is made up of a personal computer etc. in which setting tools are installed.
Patent Document 1 describes a technology to enable handling a new apparatus or network that cannot be handled with the existing configuration editor without greatly changing the design devices of a system made up of a network and a PLC.
Patent Document 2 describes a technology to, in a data communication device connectable to a network including a plurality of apparatuses, search for the apparatus that can additionally be connected on the basis of information about communication ports of the apparatus and provide display for identifying the searched apparatus.
Patent Document 3 describes a technology to build a topology by automatically deciding where the topology has loops and solving the loops, which are recognized as being disconnected.
Patent Document 4 describes a technology to, based on connection information which indicates a cable connection relations about a plurality of connection ports with the other devices, identify the connection port to which a cable should be connected and light up a lighting portion mounted for each of the connection ports such that the identified connection port may be distinguished from the others.